1. Field of the Invention
The invention relates to mobile network management, especially to a multicast management mechanism for mobile networks, which proposes a multicast table approach to support multicast that minimizes the paging cost.
2. Description of Related Art
In 3GPP 43.068 specification, Global System for Mobile Communications or Universal Mobile Telecommunications System (GSM/UMTS) provide voice group call service through a broadcast mechanism. Specifically, all service areas are paged when a voice call is delivered. In FIG. 1, a GSM/UMTS service area is partitioned into several location areas (LAs), such as LA1–LA3, LA4–LA6, or LA7–LA8, and communicates with a mobile switching center (MSC) such as 40, 60 or 80, having a respective visitor location register (VLR) such as 50, 70 or 90. The remaining numbers in FIG. 1 will be described later. As shown in FIG. 1, a typical GSM/UMTS (shown in chapter 8 of 3GPP TS 09.02 specification) will page all service areas (step 5) even if location areas LA2, LA4, LA5, LA7, and LA8 do not contain any multicast users such as 100–103. Additionally, as shown in FIG. 2, multicast is achieved in iSMS (shown in “iSMS: An Integration Platform for Short Message Service and IP Networks”, IEEE Network, March/April 2001, by Herman Chung-Hwa Rao, Di-Fa Chang, and Yi-Bing Lin) by sending every message to individual user on a multicast list. This can avoid messages being sent to a location area without a multicast user, as that shown in FIG. 1. However, if n users are in a service area, the same message is sent n times to this service area. For example, the same message is sent twice to the location area LA1 for users 100 and 101. The remaining numbers will be described later. The above two approaches are clearly not effective. Neither existing 2G systems with voice function or existing 3G systems with multimedia function can support efficient multicasting.